Improvement in devices for releasing screw-engines



UNITED STATES PATENT OFFICE.

ANTONA KIEFFR, OF BUFFALO, NEW YORK, ASSIGNOR TO HIMSELF AND JAMESKENNELLY, OF SAME PLACE.

IMPROVEMENT IN DEVICES FOR RELEASING SCREW-ENGINES.

Specification forming part-of Letters Patent No. 48,339, dated June 20, 1865.

to the accompanying drawings, and the letters of reference marked thereon, in which` Figure I is a side elevation of a screw-propeller engine, showing the construction and mode of attachin g my improved device thereto. Fig. II is a vertical transverse section of same.

The nature of this invention consists in the combination, with the prying-off wheel on the crank-shaft of a screw-propeller engine, of a prying-off' lever and pawl, said lever leading directly (or through a combination of levers, as circumstances may require) to the engineers room, in such manner that the engineer standing at his post, within reach of the throt- V tle and reversing levers of the engine, may

operate said pryingoftl lever when from unskillful management or other canse his engine stops 011 a dead-center, and by its action revolve the crank-shaft sufficiently to carry the engine past said dead-center and allow it to `resume its motion.

Letters ot' like name and kind refer to like parts in each of the figures.

A represents the crank or screw shaft of a screw-propeller engine.

B represents a toothed or ratchet wheel, commonly called the prying-oi` wheel, keyed or otherwise secured upon the crank-shaft A at any convenient point.

C represents a prying-oli' lever, having its fulcrum at c', and carrying a pawl or dog, D, which may be made to engage the teeth of the prying-off wheel B when required. The lever C projects up through the engineers platform or engine-room floor E at such point as to be `within the reach of the engineer standing at moving the pressure upon the pawl-rod it will disengage itselfl from the teeth of the pryingoff wheel, and in that position remain until again required to be thrown into action. When, from unskillt'ul management of the engineer in stopping or reversing his engine, it becomes caught on one of its dead-centers, (as frequently happens,) so that the pressure of steam ou the piston is powerless to move or start the engine, the engineer, by placing his foot on the pawlrod and throwing the pawl into the teeth of the prying-oft' wheel and giving a single vibratory movement to the prying-oft' lever, may revolve the crank-shaft past its dead-center and allow the engine to resume its motion. This can be accomplished instantly and without loss of time.

The device at present in use, so far as my knowledge goes, is simply a detached lever or bar, the end of which is inserted into the teeth of the prying-off wheel, and a fulcrnrn. formed by resting it on a block or other temporary or imperfect device. This evidentlyv requires the engineer lo leave his post and go below, s0 that much time and trouble are required to release his engine when caught on the center. Tugboat engines, which require to be frequently and quickly stopped and reversed, are peculiarly liable to this difficulty, and to them my invention is peculiarly applicable and of' the first importance. Its use has and will in many instances, by giving a more quick and perfect control ot' the engine, avoid accident .and destruction of property. v

In applying my invention to engines of different construction it is evident that Yin some.

cases a compound lever or a combination of levers may be required to make the connection ANTONA KIEFFER.

Witnesses: v

GEO. W. WALLACE, B. H. MUEBLE. 

